Let’s suppose we want to observe a recently discovered GRB from
Cambridge, UK. We have the location of the event, already converted to
astropy co-ordinates. This means we can use astropy’s Alt-Az
conversions to calculate the altitude of the target at any given time.

(This section borrows heavily from
http://docs.astropy.org/en/stable/coordinates/observing-example.html,
consult the original for more detail and background)